The invention relates to latch mechanisms on vehicles such as tanks and armored personnel carriers, but the invention has other applications as well.
Combat vehicles need to protect their crews from nuclear, biological and chemical agents extant in modern warfare. These vehicles also perform the more traditional function of protecting occupants from explosions and enemy fire. Hatches and doors on combat vehicles accordingly must withstand the impacts of explosions and projectiles while maintaining a seal against the aforementioned agents. Latches for doors and hatches must maintain positive closure thereof despite the explosive impacts and despite shocks to the vehicle resulting from rapid travel over rough terrain.
I address the above needs via a hatch securing mechanism whose base attaches to a door frame or hatchway and whose hasp attaches to a door or hatch lid. The base defines a retainer and a pinway element between which the hasp stays during closure of the door or lid. A latch pin translatable in the pinway element has a tip slidable against a bevelled surface of the hasp. The tip's sliding motion forces the hasp into tighter, locked engagement with the base. A groove segment on the latch pin spirals about the pin's axis, and a stud in the pinway element tracks the groove segment such that rotating the pin effects its translation. The action of the latch pin also compresses an elastically deformable seal between the door and door frame so that the seal is increasedly effective against explosive blast pressures. Lock means are provided for keeping the latch pin in a hasp retaining position unless the pin is manually moved.